Figure 1. Neutralization against SARS-CoV-2 variants.

Mouse neutralizing antibody titers against SARS-CoV-2 variants were measured over time using an FRNT₅₀ assay. (A) Schematic of intranasal mouse infection and sera collection. (A–E) Variants included were (B) B.1.351, (C) BA.2.12.1, (D) BA.5, and (E) XBB.1.5. Naive mice were uninfected. (B) B.1.351 (n = 10) and naive (n = 5). (C) BA.2.12.1 (n = 7) and naive (n = 5). (D) BA.5 (n = 32) and naive (n = 5). (E) XBB.1.5 (n = 19) and naive (n = 5). Antibody titers were determined by the highest antibody dilution that resulted in a 50% reduction in the number of foci. 50% serum neutralization titers (NT₅₀) are listed above each group. Limit of detection (LOD) = 20 PFU. P values were measured by 1-way ANOVA followed by Tukey’s test for multiple comparisons. ***P < 0.001, ****P < 0.0001.